These bogus Tech Support alerts are shown in such a way as to trick the user into thinking their computer has crashed or that a virus has been detected on the computer. It does this to try and scare the infected user into calling one of the listed numbers in order to receive support. In reality, though, they will only be greeted with people who are trying to sell them unneeded support contracts and services.
Some counterfeit and third party power adapters and batteries may not be designed properly and could result in safety issues. To ensure you receive a genuine Apple battery during a battery replacement, we recommend visiting an Apple Store or Apple Authorized Service Provider. If you need a replacement adapter to charge your Apple device, we recommend getting an Apple power adapter.